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1802d0be | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1b2b03f8 KK |
2 | /* |
3 | * | |
4 | * general timer device for using in ISDN stacks | |
5 | * | |
6 | * Author Karsten Keil <kkeil@novell.com> | |
7 | * | |
8 | * Copyright 2008 by Karsten Keil <kkeil@novell.com> | |
1b2b03f8 KK |
9 | */ |
10 | ||
11 | #include <linux/poll.h> | |
12 | #include <linux/vmalloc.h> | |
5a0e3ad6 | 13 | #include <linux/slab.h> |
1b2b03f8 KK |
14 | #include <linux/timer.h> |
15 | #include <linux/miscdevice.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/mISDNif.h> | |
76a64921 | 18 | #include <linux/mutex.h> |
174cd4b1 IM |
19 | #include <linux/sched/signal.h> |
20 | ||
5b834354 | 21 | #include "core.h" |
1b2b03f8 | 22 | |
76a64921 | 23 | static DEFINE_MUTEX(mISDN_mutex); |
dfa96ec1 | 24 | static u_int *debug; |
1b2b03f8 KK |
25 | |
26 | ||
27 | struct mISDNtimerdev { | |
28 | int next_id; | |
29 | struct list_head pending; | |
30 | struct list_head expired; | |
31 | wait_queue_head_t wait; | |
32 | u_int work; | |
33 | spinlock_t lock; /* protect lists */ | |
34 | }; | |
35 | ||
36 | struct mISDNtimer { | |
37 | struct list_head list; | |
38 | struct mISDNtimerdev *dev; | |
39 | struct timer_list tl; | |
40 | int id; | |
41 | }; | |
42 | ||
43 | static int | |
44 | mISDN_open(struct inode *ino, struct file *filep) | |
45 | { | |
46 | struct mISDNtimerdev *dev; | |
47 | ||
48 | if (*debug & DEBUG_TIMER) | |
49 | printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep); | |
50 | dev = kmalloc(sizeof(struct mISDNtimerdev) , GFP_KERNEL); | |
51 | if (!dev) | |
52 | return -ENOMEM; | |
53 | dev->next_id = 1; | |
54 | INIT_LIST_HEAD(&dev->pending); | |
55 | INIT_LIST_HEAD(&dev->expired); | |
56 | spin_lock_init(&dev->lock); | |
57 | dev->work = 0; | |
58 | init_waitqueue_head(&dev->wait); | |
59 | filep->private_data = dev; | |
6bff338b | 60 | return nonseekable_open(ino, filep); |
1b2b03f8 KK |
61 | } |
62 | ||
63 | static int | |
64 | mISDN_close(struct inode *ino, struct file *filep) | |
65 | { | |
66 | struct mISDNtimerdev *dev = filep->private_data; | |
c08c464d | 67 | struct list_head *list = &dev->pending; |
1b2b03f8 KK |
68 | struct mISDNtimer *timer, *next; |
69 | ||
70 | if (*debug & DEBUG_TIMER) | |
71 | printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep); | |
c08c464d AV |
72 | |
73 | spin_lock_irq(&dev->lock); | |
74 | while (!list_empty(list)) { | |
75 | timer = list_first_entry(list, struct mISDNtimer, list); | |
76 | spin_unlock_irq(&dev->lock); | |
77 | del_timer_sync(&timer->tl); | |
78 | spin_lock_irq(&dev->lock); | |
79 | /* it might have been moved to ->expired */ | |
80 | list_del(&timer->list); | |
1b2b03f8 KK |
81 | kfree(timer); |
82 | } | |
c08c464d AV |
83 | spin_unlock_irq(&dev->lock); |
84 | ||
1b2b03f8 KK |
85 | list_for_each_entry_safe(timer, next, &dev->expired, list) { |
86 | kfree(timer); | |
87 | } | |
88 | kfree(dev); | |
1b2b03f8 KK |
89 | return 0; |
90 | } | |
91 | ||
92 | static ssize_t | |
c46f0a2d | 93 | mISDN_read(struct file *filep, char __user *buf, size_t count, loff_t *off) |
1b2b03f8 KK |
94 | { |
95 | struct mISDNtimerdev *dev = filep->private_data; | |
ebb06be1 | 96 | struct list_head *list = &dev->expired; |
1b2b03f8 | 97 | struct mISDNtimer *timer; |
1b2b03f8 KK |
98 | int ret = 0; |
99 | ||
100 | if (*debug & DEBUG_TIMER) | |
101 | printk(KERN_DEBUG "%s(%p, %p, %d, %p)\n", __func__, | |
475be4d8 | 102 | filep, buf, (int)count, off); |
1b2b03f8 | 103 | |
ebb06be1 AV |
104 | if (count < sizeof(int)) |
105 | return -ENOSPC; | |
106 | ||
107 | spin_lock_irq(&dev->lock); | |
108 | while (list_empty(list) && (dev->work == 0)) { | |
109 | spin_unlock_irq(&dev->lock); | |
1b2b03f8 KK |
110 | if (filep->f_flags & O_NONBLOCK) |
111 | return -EAGAIN; | |
112 | wait_event_interruptible(dev->wait, (dev->work || | |
ebb06be1 | 113 | !list_empty(list))); |
1b2b03f8 KK |
114 | if (signal_pending(current)) |
115 | return -ERESTARTSYS; | |
ebb06be1 | 116 | spin_lock_irq(&dev->lock); |
1b2b03f8 | 117 | } |
1b2b03f8 KK |
118 | if (dev->work) |
119 | dev->work = 0; | |
ebb06be1 AV |
120 | if (!list_empty(list)) { |
121 | timer = list_first_entry(list, struct mISDNtimer, list); | |
1b2b03f8 | 122 | list_del(&timer->list); |
ebb06be1 | 123 | spin_unlock_irq(&dev->lock); |
c46f0a2d | 124 | if (put_user(timer->id, (int __user *)buf)) |
1b2b03f8 KK |
125 | ret = -EFAULT; |
126 | else | |
127 | ret = sizeof(int); | |
128 | kfree(timer); | |
ebb06be1 AV |
129 | } else { |
130 | spin_unlock_irq(&dev->lock); | |
1b2b03f8 KK |
131 | } |
132 | return ret; | |
133 | } | |
134 | ||
afc9a42b | 135 | static __poll_t |
1b2b03f8 KK |
136 | mISDN_poll(struct file *filep, poll_table *wait) |
137 | { | |
138 | struct mISDNtimerdev *dev = filep->private_data; | |
a9a08845 | 139 | __poll_t mask = EPOLLERR; |
1b2b03f8 KK |
140 | |
141 | if (*debug & DEBUG_TIMER) | |
142 | printk(KERN_DEBUG "%s(%p, %p)\n", __func__, filep, wait); | |
143 | if (dev) { | |
144 | poll_wait(filep, &dev->wait, wait); | |
145 | mask = 0; | |
146 | if (dev->work || !list_empty(&dev->expired)) | |
a9a08845 | 147 | mask |= (EPOLLIN | EPOLLRDNORM); |
1b2b03f8 KK |
148 | if (*debug & DEBUG_TIMER) |
149 | printk(KERN_DEBUG "%s work(%d) empty(%d)\n", __func__, | |
475be4d8 | 150 | dev->work, list_empty(&dev->expired)); |
1b2b03f8 KK |
151 | } |
152 | return mask; | |
153 | } | |
154 | ||
155 | static void | |
e313ac12 | 156 | dev_expire_timer(struct timer_list *t) |
1b2b03f8 | 157 | { |
e313ac12 | 158 | struct mISDNtimer *timer = from_timer(timer, t, tl); |
1b2b03f8 KK |
159 | u_long flags; |
160 | ||
161 | spin_lock_irqsave(&timer->dev->lock, flags); | |
1b108956 AV |
162 | if (timer->id >= 0) |
163 | list_move_tail(&timer->list, &timer->dev->expired); | |
1b2b03f8 | 164 | wake_up_interruptible(&timer->dev->wait); |
bdcc5bc2 | 165 | spin_unlock_irqrestore(&timer->dev->lock, flags); |
1b2b03f8 KK |
166 | } |
167 | ||
168 | static int | |
169 | misdn_add_timer(struct mISDNtimerdev *dev, int timeout) | |
170 | { | |
475be4d8 | 171 | int id; |
1b2b03f8 KK |
172 | struct mISDNtimer *timer; |
173 | ||
174 | if (!timeout) { | |
175 | dev->work = 1; | |
176 | wake_up_interruptible(&dev->wait); | |
177 | id = 0; | |
178 | } else { | |
179 | timer = kzalloc(sizeof(struct mISDNtimer), GFP_KERNEL); | |
180 | if (!timer) | |
181 | return -ENOMEM; | |
1678ec00 | 182 | timer->dev = dev; |
e313ac12 | 183 | timer_setup(&timer->tl, dev_expire_timer, 0); |
1678ec00 AV |
184 | spin_lock_irq(&dev->lock); |
185 | id = timer->id = dev->next_id++; | |
1b2b03f8 KK |
186 | if (dev->next_id < 0) |
187 | dev->next_id = 1; | |
188 | list_add_tail(&timer->list, &dev->pending); | |
1b2b03f8 KK |
189 | timer->tl.expires = jiffies + ((HZ * (u_long)timeout) / 1000); |
190 | add_timer(&timer->tl); | |
1678ec00 | 191 | spin_unlock_irq(&dev->lock); |
1b2b03f8 KK |
192 | } |
193 | return id; | |
194 | } | |
195 | ||
196 | static int | |
197 | misdn_del_timer(struct mISDNtimerdev *dev, int id) | |
198 | { | |
1b2b03f8 | 199 | struct mISDNtimer *timer; |
1b2b03f8 | 200 | |
1b108956 | 201 | spin_lock_irq(&dev->lock); |
1b2b03f8 KK |
202 | list_for_each_entry(timer, &dev->pending, list) { |
203 | if (timer->id == id) { | |
204 | list_del_init(&timer->list); | |
1b108956 AV |
205 | timer->id = -1; |
206 | spin_unlock_irq(&dev->lock); | |
207 | del_timer_sync(&timer->tl); | |
1b2b03f8 | 208 | kfree(timer); |
1b108956 | 209 | return id; |
1b2b03f8 KK |
210 | } |
211 | } | |
1b108956 AV |
212 | spin_unlock_irq(&dev->lock); |
213 | return 0; | |
1b2b03f8 KK |
214 | } |
215 | ||
703c631e AB |
216 | static long |
217 | mISDN_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) | |
1b2b03f8 KK |
218 | { |
219 | struct mISDNtimerdev *dev = filep->private_data; | |
220 | int id, tout, ret = 0; | |
221 | ||
222 | ||
223 | if (*debug & DEBUG_TIMER) | |
224 | printk(KERN_DEBUG "%s(%p, %x, %lx)\n", __func__, | |
475be4d8 | 225 | filep, cmd, arg); |
76a64921 | 226 | mutex_lock(&mISDN_mutex); |
1b2b03f8 KK |
227 | switch (cmd) { |
228 | case IMADDTIMER: | |
229 | if (get_user(tout, (int __user *)arg)) { | |
230 | ret = -EFAULT; | |
231 | break; | |
232 | } | |
233 | id = misdn_add_timer(dev, tout); | |
234 | if (*debug & DEBUG_TIMER) | |
235 | printk(KERN_DEBUG "%s add %d id %d\n", __func__, | |
475be4d8 | 236 | tout, id); |
1b2b03f8 KK |
237 | if (id < 0) { |
238 | ret = id; | |
239 | break; | |
240 | } | |
241 | if (put_user(id, (int __user *)arg)) | |
242 | ret = -EFAULT; | |
243 | break; | |
244 | case IMDELTIMER: | |
245 | if (get_user(id, (int __user *)arg)) { | |
246 | ret = -EFAULT; | |
247 | break; | |
248 | } | |
249 | if (*debug & DEBUG_TIMER) | |
250 | printk(KERN_DEBUG "%s del id %d\n", __func__, id); | |
251 | id = misdn_del_timer(dev, id); | |
252 | if (put_user(id, (int __user *)arg)) | |
253 | ret = -EFAULT; | |
254 | break; | |
255 | default: | |
256 | ret = -EINVAL; | |
257 | } | |
76a64921 | 258 | mutex_unlock(&mISDN_mutex); |
1b2b03f8 KK |
259 | return ret; |
260 | } | |
261 | ||
eac74af9 | 262 | static const struct file_operations mISDN_fops = { |
89b107ad | 263 | .owner = THIS_MODULE, |
1b2b03f8 | 264 | .read = mISDN_read, |
1b2b03f8 | 265 | .poll = mISDN_poll, |
703c631e | 266 | .unlocked_ioctl = mISDN_ioctl, |
1b2b03f8 KK |
267 | .open = mISDN_open, |
268 | .release = mISDN_close, | |
6038f373 | 269 | .llseek = no_llseek, |
1b2b03f8 KK |
270 | }; |
271 | ||
272 | static struct miscdevice mISDNtimer = { | |
273 | .minor = MISC_DYNAMIC_MINOR, | |
274 | .name = "mISDNtimer", | |
275 | .fops = &mISDN_fops, | |
276 | }; | |
277 | ||
278 | int | |
dfa96ec1 | 279 | mISDN_inittimer(u_int *deb) |
1b2b03f8 KK |
280 | { |
281 | int err; | |
282 | ||
283 | debug = deb; | |
284 | err = misc_register(&mISDNtimer); | |
285 | if (err) | |
286 | printk(KERN_WARNING "mISDN: Could not register timer device\n"); | |
287 | return err; | |
288 | } | |
289 | ||
290 | void mISDN_timer_cleanup(void) | |
291 | { | |
292 | misc_deregister(&mISDNtimer); | |
293 | } |